Radiant energy source



Filed April 16. 1952 dot INVENTOR LAD/SLAS GOLDSTE/N ATTORNEY United States Patent RADIANT ENERGY SOURCE Ladislas Goldstein, Urbana, lll., assignor to International Telephone and Telegraph Corporation, a corporation of Maryland Filed Apr. 16, 1952, Ser. No. 282,723

6 Claims. 01. 331-78) This invention relates to sources of radiant energy and more particularly to radiant energy having a high density electron gas as its source.

When the gaseous fuels of rocket and jet engines are consumed by high temperature combustion, the exhaust gases emitted from these engines are highly ionized and contain regions in which high electron densities are built up which may persist for a considerable time. It is known that in a high electron density gas, radio frequency radiations are generated. The frequency of the R.-F. energy generated in a high electron density gas is related to the density of the electron gas, due to the space charge variations, e.g. the oscillations of the electron density around a mean value. These electron density oscillations give rise to the so-called plasma frequencies of an ionized gas.

An object of this invention is to utilize the R.-F. energy created in the high temperature combustion gases such as produced by rocket and jet engines, i.e., thermal reaction engines.

Another object of this invention is to control the R.-F. energy created in high temperature combustion gases.

One feature of this invention is the use of a cavity resonator in the exhaust gas passage of a rocket or jet engine through which or adjacent which the exhaust gases must pass. R.-F. energy is coupled from these gases at a frequency dependent upon the resonant frequency of the cavity. The persistence and amount of R.-F. power generated in the exhaust gas is controlled by introduction into the gas stream of electro-negative atoms or molecules, i.e., negative type particles.

The above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a schematic illustration according to the principles of this invention of a rocket engine having a cavity resonator to couple the R.-F. energy from the high temperature combustion gases, and means for controlled introduction of electro-negative molecules and/or atoms into the gas stream to reduce the persistency of the R.-F. energy created in the high temperature combustion gases of a rocket engine;

Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1; and

Fig. 3 is a cross-sectional view similar to Fig. 2 of a modification of the invention.

Referring to Figs. 1 and 2, a source of R.-F. energy according to the principles of this invention may comprise a mobile craft 1 having a jet or rocket engine shown generally at 2. The fuel to drive the mobile craft 1 is consumed in the combustion chamber 3, and the exhaust of the engine is emitted through the exhaust gas passage 3a. The exhaust of a rocket or jet engine contains gases having a high electron density as a result of the high temperature combustion of the fuel inside the combustion chamber 3. It is known that the high temperature combustion gases escaping from rocket or jet engines are highly ionized, and the electron density variations within the gas give rise to broad band "plasma frequencies." In the device shown in Fig. 1, these high temperature combustion gases are directed through an appropriatelyshaped resonant cavity, for purposes of illustration herein shown in the form of a circular section of Waveguide 4. The dimensions of the cavity are such that it is resonant at a desired R.-F. output. An output coupling 5, such as a probe, loop, or waveguide iris, is utilized to couple the R.-F. energy from the cavity resonator 4 to suitable transmitter circuits, such as an R.-F. amplifier 6, modulator 7, coupler 8, and antenna 9, located of course, within the shell of the rocket. The antenna 9, and also antenna 13, may be of the slot or surface type formed in or associated with the shell of the craft. In lieu of these usual transmitter circuits, any other means for utilizing R.-F. energy may be coupled to probe 5. Thus the R.-F. energy in the exhaust gases from the engine, at a desired frequency, is coupled to utilization apparatus by means of the resonant cavity 4 and output coupling 5.

The R.-F. energy created in the trail of high temperature combustion gases may be reduced by the addition of electro-negative atoms in accordance with the principles of this invention. To minimize the R.-F. energy, it is necessary to suppress the ionized gas in the shortest possible time. It is known that the electrons in the gas will disappear by diffusion, recombination, or attachment. The pure electron positive ion recombination is very slow, thus if only recombination is relied on to cause the disappearance of the electrons in the exhaust gases, the ionized trail will persist for long periods. Electron attachment by electro-negative atoms or molecules in a pressure zone accelerates the electron density decay in the exhaust gases and also increases the recombination process resulting in a decrease in the ion density.

To cause electron attachment and/or recombination, it is necessary to use highly electro-negative atoms and/or molecules emitted in adequate concentration with the exhaust gases. Thus, a tank 10 of electro-negative atoms and/or molecules is provided in the body of the mobile craft 1. The most strongly electro-negative atoms are the halogen atoms and, under favorable conditions, molecules containing halogen atoms. The gases contained in the tank 10 for mixture with the high temperature combustion gases can be otherwise chemically neutral electrical gases composed entirely or partly of strongly electronegative atoms, which under conditions of disassociation are liberated and then exercise the elfect of their electronegativity such as to produce electron attachment. Such molecules, for example, are CCl (carbon tetrachloride), CCI F (dichlorodifluoromethane), (1P (carbon tetrafiuoride), or SF (sulfur hexafluoride). The emission of these gases from the tank 10 is controlled by a valve 11 which is responsive to control circuit 12. The control circuit 12 which opens or shuts the valve 11 may be operated manually, or by wire, but as shown, it is preferably by remote radio control. Wire control may be used to release the gases from the tank 10 for mixture with the exhaust gases.

In Fig. 3, I show a modification of the exhaust passage 3a wherein the cavity section is subdivided into a plurality of resonant cavities 14 disposed radially about the axis of the passageway and in communication therewith. By this arrangement cavities of small size may be had without causing any unbalance.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made by way of example only and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

I claim:

1. A source of radio frequency energy comprising means for producing a stream of ionized high temperature gases having a high electron density, means to control the electron density of said gases, and means to extract radio frequency energy from said stream, said means to control the electron density including means to mix electronegative particles with said high temperature gases.

2. A source of radio frequency energy comprising means for producing a stream of ionized high temperature gases having a high electron density, means to control the electron density of said gases, and means to extract radio frequency energy from said stream, said means to control the electron density including means to mix atoms of the halogen group with said high temperature gases.

3. A source of radio frequency energy comprising means for producing a stream of ionized high temperature gases having a high electron density, means to control the electron density of said gases, and means to extract radio frequency energy from said stream, said means to control the electron density including means to mix electro-negative molecules with said high temperature combustion gases.

4. In a thermal reaction engine having a stream of ionized high temperature combustion gases of high electron density, a source of gas containing electro-negative atoms and means for introducing gas from said source into said stream of gases to control the electron density thereof.

5. In a thermal reaction engine according to claim 4, wherein the gas of said source is selected from the halogen group.

6. The process of utilizing radio frequency energy created in high temperature gases produced by thermal reaction engines comprising selecting a portion of the stream of ionized high temperature combustion gases which has a high electron density, and controlling the electron density of said gases by mixing electronegativetype gases with said combustion gases in said portions of said stream.

References Cited in the file of this patent FOREIGN PATENTS Great Britain Dec. 13, 1922 Germany Jan. 2, 1939 OTHER REFERENCES 

